This project will examine the effects of two drugs of abuse, phencyclidine hydrochloride (PCP) and delta-9-tetrahydrocannabinol (THC) on reproductive functions of the rat when given by themselves and in combination with each other. The effect of both short- and long-term administration of these drugs will be examined. Our studies will focus on changes in marker proteins and key enzymes specific to Leydig cells and Sertoli cells in the testis. Testicular production of male hormone will be assessed, as well as the effect of these drugs and drug combinations on the pituitary and hypothalamic output of gonadotropins and gonadotropin releasing factor. Blood levels of testicular hormones will be examined. Electron microscopic examination of pituitary and testis may provide an ultrastructural basis to correlate with observed change in function of these organs. The data obtained will provide unique insight into how these two drugs of abuse, when used by themselves or in combination with one another, might effect human reproductive functions using the rat as an enzymatic and hormonal model for man.